HR: 11:40h
AN: H52A-05 INVITED     [Abstracts]
TI: Stochastic Modelling of Monthly Runoff From Multiple Sites in a Semi-arid Region
AU: * Rosbjerg, D
EM: dr@er.dtu.dk
AF: Environment & Resources DTU, Technical University of Denmark, Building 115, Kongens Lyngby, DK-2800 Denmark
AU: Kjeldsen, T R
EM: trkj@ceh.ac.uk
AF: Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, OX10 8BB United Kingdom
AB: The identification, estimation and generation of a multivariate time series model for monthly runoff from eight sub-catchments of the Mupfure catchment in Zimbabwe have been accomplished taking into account the fact that entire years of zero runoff may occur. The occurrence of years with no runoff at four of the eight sub-catchments was acknowledged in the simulation model through conditional probabilities for zero runoff and subsequent adjustments due to the fact that zero runoff is more likely in dry than in wet years. The model in its present state cannot encompass correlation between successive years. The expected occurrence of months with zero flow during the dry season in all the sub-catchments has led to the adoption of a non-parametric disaggregation method, the method of fragments, for generation of monthly flow based on the generated annual flow. In this study, a multivariate extension of the method of fragments has been implemented. The stochastic simulation model has been verified and validated, and the statistical properties of the historical streamflows are shown to be satisfactorily reproduced.
DE: 1860 Runoff and streamflow
DE: 1869 Stochastic processes
SC: Hydrology [H]
MN: 2005 Joint Assembly